The present invention relates to a new and distinct cultivar of small-leaved Boxwood grown as an ornamental evergreen shrub for use in the landscape and as a specimen or hedging plant in the garden. The new cultivar is known botanically as Buxus microphylla ‘ROBBUXUPT’ and will be referred to hereinafter by the cultivar name ‘ROBBUXUPT’.
‘ROBBUXUPT’ was discovered in 1989 at the inventor's nursery in Grain Valley, Mo. as a naturally occurring sport which the inventor discovered growing within a commercial crop of Buxus microphylla ‘Wintergreen’ (unpatented). The inventor observed that the new variety, ‘ROBBUXUPT’, exhibited a distinctive columnar form and bore noticeably darker green foliage than the sport parent variety, ‘Wintergreen’. In subsequent years, the inventor observed that ‘ROBBUXUPT’ remained evergreen through the winter whereas the foliage of ‘Wintergreen’ loses its green color and turns bronze.
The inventor first asexually propagated ‘ROBBUXUPT’ in 1990 at the inventor's nursery in Grain Valley, Mo., using tip cuttings. Rooting was successful and the grown-on plants exhibited the characteristic habit and leaf color of the initial discovery. The inventor has determined that the distinguishing characteristics of ‘ROBBUXUPT’ remain stable and uniform in successive generations of asexual reproduction.